The provision of special schools varies around the country

Schools Minister Andrew Adonis said "strong guidance" would be issued to local authorities in England.

He made the announcement on the eve of a conference on special educational needs organised by the Conservatives.

The Tories accuse Labour of presiding over the closure of special schools, forcing pupils into mainstream classes.

Lord Adonis said: "If a local authority proposes a special school closure they must clearly demonstrate that the new provision they are putting in place is better than what was there before.

"This test will provide added protection and a guarantee to local communities, children and parents that SEN provision in their area can only get better."

Officials at the Department for Education and Skills said the guidance would not be issued until next summer.

But in the meantime local authorities would be expected to be mindful that it was on the way.

Lord Adonis also announced that the mandatory training of school Sencos - special educational needs co-ordinators - previously announced by the education secretary, was "a top priority".

The training would be piloted from next year and would apply to all new Sencos from 2008.

'Increased funding'

Sencos played a key role in ensuring SEN had the right profile in schools and that parents had confidence their child's needs were being identified and met, he said.

His department stressed that funding for SEN had been increased, with more resources going to schools to support earlier intervention than ever before.

But this has been a fraught issue for some time.

A report from the Commons education select committee in July said the system of education for pupils with special needs in England was "not fit for purpose".

It called for stronger government guidelines for councils, to end a "postcode lottery" of provision.

And it said the government's "inclusion" policy - teaching pupils in mainstream schools wherever possible - was causing confusion about whether this meant special schools should close.

Conservative leader David Cameron has called for a moratorium on special school closures.